The revelation that the suspected New York City bomber was born in Afghanistan before becoming a U.S. citizen prompted Republicans to attack the U.S. government's immigrant screening process.

Following the apprehension of Ahmad Khan Rahami, who immigrated with his family to the U.S., Republican presidential nominee Donald Trump and GOP lawmakers said the government doesn't know enough about people from countries with terror connections — such as Afghanistan, Iraq, Syria and Somalia — to allow their continued access into the U.S.

"These attacks, and many others, were made possible because of our extremely open immigration system, which fails to properly vet and screen the individuals or families coming into our country," Trump said during a campaign stop in Estero, Fla. "Immigration security is national security."

Senate Majority Leader Mitch McConnell, R-Ky., took to the Senate floor Monday to discuss national security threats facing the U.S. from terrorists abroad and those who have entered the country. Sen. Marco Rubio, R-Fla., said the attacks were a reminder that the country needs to "enhance the vetting of immigrants to ensure we are not granting citizenship or refugee status to terrorists."

Rep. Jeff Duncan, R-S.C., said the U.S. must “indefinitely suspend” all forms of immigration from countries classified as terrorist safe havens by the State Department. Rep. Steve King, R-Iowa, said on Twitter that the country's news media will continue featuring "terrorist attacks followed by press conferences featuring their enablers."

Those sentiments were compounded by a Department of Homeland Security internal audit released Monday that found 858 people were mistakenly granted U.S. citizenship even though they had deportation orders pending against them. The audit blamed DHS and the FBI for failing to digitize all their fingerprint files, which allowed people to apply for citizenship using fake identities.

Rep. Michael McCaul, R-Texas, chairman of the House Homeland Security Committee, has long argued that the federal government doesn't have the tools to properly vet people coming from countries with ties to Islamic extremism. He pointed to Monday's DHS audit as proof.

"In order to prevent individuals like these from slipping through the cracks, we must quickly digitize old fingerprint cards and bring our immigration process into the 21st century," he said.

Many Democrats have criticized Trump for scapegoating immigrants with his calls to build a giant wall along the southern border and temporarily halt all immigration from Muslim countries.

But after the shooting rampage in San Bernardino, Calif., by a U.S. native and his Pakistani wife, who apparently radicalized him, Democratic Sen. Dianne Feinstein of California pushed a bill to restrict people entering through a special visa waiver program if they had visited Iraq or Syria in the previous five years.

In the immediate aftermath of the Paris attacks last November, when some believed the perpetrators included Syrians who entered France as war refugees, some Democrats questioned whether the U.S. should halt its Syrian refugee program. None of the attackers was confirmed to be Syrian, but the worry was enough for some, like Sen. Charles Schumer, D-N.Y., to suggest a "pause" in the Syrian refugee program to ensure the system was working.

And on Monday, Democratic presidential nominee Hillary Clinton said she has long supported improvements to the country's ability to vet immigrants. "I am absolutely in favor of, and have long been an advocate for, tough vetting," she said.

All the while, the Obama administration has defended its ability to screen foreigners trying to enter the U.S. Just last week, the administration announced its plan to increase the number of refugees to 110,000, up from 85,000 this year and 70,000 a year from 2013 through 2015.

In the past year, DHS has repeatedly defended its screening procedures: Refugees must undergo in-person interviews abroad and have their names run through federal terrorism and criminal databases. Syrian refugees go through more screening, where federal officials check their backgrounds against classified information, a process that can take up to two years to complete.

DHS Secretary Jeh Johnson has acknowledged that the system could be improved but told USA TODAY last November that the system was sound.

"We now do a better job of connecting dots, consulting all the right databases and systems that we have available to us," he said.

Members of the FBI and other law enforcement officials investigate an Elizabeth, N.J. residence in connection with a series of bombs found in New York and New Jersey, on Sept. 19, 2016. Drew Angerer, Getty Images

A surveillance image made available by the New Jersey State Police showing Ahmad Khan Rahami. New York, New Jersey and Federal authorities say Rahami is wanted in connection with multiple bombing incidents in New Jersey and New York City. New Jersey State Police via European Pressphoto Agency

New York Mayor Bill de Blasio, right, and New York Gov. Andrew Cuomo, second from right, look over a mangled construction toolbox, Sept. 18, 2016, while touring the site of an explosion that occurred Saturday night in the Chelsea neighborhood of New York. Numerous people were injured in the blast, and the motive, while reportedly not international terrorism, is still being investigated. Pool photo by Justin Lane

New York Mayor Bill de Blasio, 3rd from left, and New York Gov. Andrew Cuomo, second from right, tour the site of an explosion that occurred overnight in the Chelsea neighborhood of New York. Pool photo by Justin Lane

New York Mayor Bill de Blasio,rear, and New York Gov. Andrew Cuomo, second from right, tour the site of an explosion that occurred in the Chelsea neighborhood of New York City. Pool photo by Justin Lane

An NYPD officer on peers out from the subway entrance on 7th Avenue and 23rd Street near the scene of an explosion on West 23rd Street Sept. 18, 2016, in New York City. Carmine Galasso, USA TODAY Network-North Jersey Media Group

New York Gov. Andrew Cuomo, center right, walks down 23rd Street where an explosive device went off last night on the left side of the mid-block section of Chelsea. Law enforcement agencies are conducting investigations. Carmine Galasso, USA TODAY Network-North Jersey Media Group

New York Gov. Andrew Cuomo departs after visiting the scene of an explosion on West 23rd Street on Sept. 18, 2016 in New York. An explosion rocked one of the most fashionable neighborhoods of New York on Saturday night. Bryan R. Smith, AFP/Getty Images

Mayor Bill de Blasio, center, and NYPD Chief of Department James O'Neill, center right, speak during a press conference near the scene of an explosion on West 23rd street in Manhattan's Chelsea neighborhood, in New York, on Saturday, Sept. 17, 2016. Andres Kudacki, AP

Passersby are redirected by police officers as the police block the street near the scene of an explosion on West 23rd Street and 6th Avenue in Manhattan's Chelsea neighborhood, as they carry on an investigation in New York, early Sunday, Sept. 18, 2016. Andres Kudacki, AP

Police officers look for suspicious packages along Fifth Avenue near the scene of an explosion on West 23rd Street and 6th Avenue in Manhattan's Chelsea neighborhood, in New York, early Sunday, Sept. 18, 2016. Andres Kudacki, AP

Members of the FBI search an area for evidence as police, firefighters and emergency workers gather at the scene of an explosion in Manhattan on September 17, 2016 in New York City. Spencer Platt, Getty Images

A vehicle with a blown out window is seen on West 23rd Street after an explosion earlier in the evening on September 17, 2016, in New York.
An explosion in New York's upscale and bustling Chelsea neighborhood injured at least 25 people, none of them in a life-threatening condition. Bryan R. Smith, AFP/Getty Images

Members of the FBI search an area for evidence as police, firefighters and emergency workers gather at the scene of an explosion in Manhattan on September 17, 2016 in New York City. Spencer Platt, Getty Images

New York Police Commissioner James O'Neill (center right) and Mayor Bill de Blasio (center left) walk into a press conference as police, firefighters and emergency workers gather at the scene of an explosion in Manhattan on September 17, 2016 in New York City. Spencer Platt, Getty Images

Heavily armed police guard the area as they search for an explosive device on West 27th Street and 7th Avenue in Manhattan's Chelsea neighborhood, in New York, early Sunday, Sept. 18, 2016. Andres Kudacki, AP

Members of the Federal Bureau of Investigation (FBI) carry on the investigations in the scene of an explosion on West 23rd Street and 6th Avenue in Manhattan's Chelsea neighborhood in New York, early Sunday, Sept. 18, 2016. Andres Kudacki, AP

Police officers look for suspicious packages along Fifth Avenue near the scene of an explosion on West 23rd Street and 6th Avenue in Manhattan's Chelsea neighborhood in New York, on Sept. 18, 2016. Andres Kudacki, AP

New York City Police Commissioner James O'Neill, center,, Mayor Bill de Blasio, right, and New York City Fire Commissioner Daniel A. Nigro address the media near the scene of the earlier explosion. Alba Vigaray, EPA

Police block a road after an explosion in New York on September 17, 2016.
An explosion in New York's Chelsea neighborhood injured multiple people Saturday night, police said. William Edwards, AFP/Getty Images